Direct access storage devices (DASD) have become part of every day life, and as such, expectations and demands continually increase for greater speed for manipulating data and for holding larger amounts of data. To meet these demands for increased performance, the mechanical assembly in a DASD device, specifically the Hard Disk Drive (HDD) has undergone many changes.
Many times the HDD is tested to determine performance of the HDD. Bit/byte error rate (BER) test is one testing method used for evaluating recording head performance. One problem with performing a BER test is that it is difficult to distinguish between disk errors and recording head errors which can lead to unreliable test results that can lead to decreased manufacturing yields.